Establishment and Characterization of a TP53-Mutated Eyelid Sebaceous Carcinoma Cell Line

Purpose

Eyelid sebaceous carcinoma (SeC) is the third most frequent eyelid malignancy worldwide and is relatively prevalent in Asian patients. An eyelid SeC cell line model is necessary for experimental research to explore the etiology and pathogenesis of eyelid SeC. This study established and characterized an eyelid SeC cell line with a TP53 mutation that might be useful for analyzing potential treatment options for eyelid SeC.

Methods

The eyelid SeC cell line SHNPH-SeC was obtained from a patient with eyelid SeC at Shanghai Ninth People's Hospital (SHNPH), Shanghai JiaoTong University School of Medicine. Immunofluorescence staining was employed to detect the origination and proliferation activity. Short tandem repeat (STR) profiling was performed for verification. Chromosome analysis was implemented to investigate chromosome aberrations. Whole exome sequencing (WES) was used to discover genomic mutations. Cell proliferation assays were performed to identify sensitivity to mitomycin-C (MMC) and 5-fluorouracil (5-FU).

Results

SHNPH-SeC cells were successively subcultured for more than 100 passages and demonstrated rapid proliferation and migration. Karyotype analysis revealed abundant chromosome aberrations, and WES revealed SeC-related mutations in TP53, KMT2C, and ERBB2. An in vivo tumor model was successfully established in NOD/SCID mice. Biomarkers of eyelid SeC, including cytokeratin 5 (CK5), epithelial membrane antigen (EMA), adipophilin, p53, and Ki-67, were detected in SHNPH-SeC cells, original tumors, and xenografts. MMC and 5-FU inhibited the proliferation and migration of SHNPH-SeC cells, and SHNPH-SeC cells presented a greater drug response than non-TP53-mutated SeC cells.

Conclusions

The newly established eyelid SeC cell line SHNPH-SeC demonstrates mutation in TP53, the most commonly mutated gene in SeC. It presents SeC properties and malignant characteristics that may facilitate the investigation of cellular behaviors and molecular mechanisms of SeC to explore promising therapeutic strategies.

HPV-associated Vulvar Intraepithelial Carcinoma With Sebaceous Differentiation: Report of 2 Cases

Sebaceous carcinoma (SC) is a malignant neoplasm demonstrating sebocytic differentiation, commonly in the periocular area. Sebocytic differentiation is recognized by multivesicular cytoplasmic clearing with frequent nuclear scalloping. The vesicles can be highlighted by immunohistochemical stains against the perilipin family proteins including adipophilin. Extraocular SC is uncommon but well reported, often in the setting of Muir-Torre syndrome; however, vulvar SC is exceptionally rare. The literature review yielded only 12 prior cases of vulvar SC, all of which showed invasion. Here we report 2 additional similar cases from 2 different institutions of an intraepithelial carcinoma with sebaceous differentiation. Histologic examination of multiple specimens from both patients showed similar features: a multifocal intraepithelial basaloid nodular neoplasm sparing the basal layer with occasional pagetoid spread. The tumor cells demonstrated a high nuclear to cytoplasmic ratio, mitoses, variably foamy vacuolated cytoplasm, and nuclear indentation. Multiple specimens from both patients showed evidence of sebaceous differentiation (substantiated by adipophilin positivity in a membranous vesicular pattern in case 1 and by androgen receptor and epithelial membrane antigen positivity in case 2), and squamous differentiation (substantiated by p63/p40 and weak CK 5/6 expression), as well as human papillomavirus (HPV) association (substantiated by p16 block positivity and detection of high-risk HPV by in situ hybridization). One case was a true in situ lesion without evidence of invasion, and the other case was predominantly an in situ carcinoma with prominent adnexal extension and focal superficial invasion of <1 mm seen in one of multiple specimens. To our knowledge, these 2 cases are the first to show a vulvar SC/carcinoma with sebaceous differentiation that is predominantly limited to the epidermis, and the first documentation of HPV infection in vulvar sebaceous neoplasms. Vulvar intraepithelial carcinoma with sebaceous differentiation is the umbrella term we chose for this entity. Whether this is a true SC in situ that is HPV positive/driven, or a vulvar intraepithelial neoplasia with sebaceous differentiation, is not entirely clear. We emphasize the importance of looking for this morphology to avoid misclassification. Due to the rarity of cases, optimal treatment at this site has not been established.

PD-L1 expression in sebaceous carcinomas

BACKGROUND

Traditional systemic treatments for unresectable, recurrent, and/or advanced sebaceous carcinoma (SC) are ineffective. Tumoral immune microenvironment characterization is essential for considering immune checkpoint inhibitors as a treatment option.

METHODS

A total of 173 resected SCs were reviewed. Clinical information, lesion size, and location were collected. Microscopic examination documented histopathologic features and expression of immunohistochemical markers PD-L1 and CD8. PD-L1 percentage was assessed amongst tumor (PD-L1 + Tu) and immune infiltrating cells (PD-L1 + Inf). Each case was attributed a combined positive score (CPS) following Head and Neck squamous cell carcinoma recommendations. PD-L1 expression was evaluated according to clinicopathologic parameters. Human Papilloma Virus presence (HPV) was analyzed using PCR microarray scanning.

RESULTS

A therapeutically relevant CPS was seen in 51.4% of cases. Higher PD-L1 + Tu, PD-L1 + Inf, and CPSs were positively associated with greater lesion size and an extraocular location. No association was seen with patient age or gender. 9.2% of SCs showed PD-L1 + Tu ≥ 1, while 52.0% showed PD-L1 + Inf ≥ 1. A higher CD8 + T-lymphocyte density was significantly associated with a higher CPS, PD-L1 + Tu, and PD-L1 + Inf. Tumor-associated T-cell infiltrate's density was higher along tumor periphery. HPV-16, HPV-43, HPV-52, and HPV-66 were detected in 8.4% of SCs. There was no significant association between HPV status, PD-L1 expression, and CPS. A significant number of SCs express PD-L1 at therapeutic levels. Nevertheless, PD-L1 expression shows a higher intertumoral heterogeneity, in extraocular than in biologically distinct periocular cases.

CONCLUSION

Our data support the need for large-scale prospective studies evaluating anti-PD-L1 immunotherapy mainly in extraocular SC treatment.

Angiogenesis in Ocular and Extraocular Sebaceous Carcinoma

To shed more light on the pathogenesis of sebaceous carcinoma, we analysed the expression of proteins related to angiogenesis in 18 ocular and 22 extraocular sebaceous carcinomas using a broad panel of immunohistochemical markers. To quantify the expression of D2-40, vascular endothelial growth factor, vascular endothelial growth factor receptor-2 and -3, we calculated a quantification score by considering the percentage of positive tumour cells (0=0%, 1=up to 1%, 2=2-10%, 3=11-50%, and 4=>50%) in relation to the staining intensity (0=negative, 1=low, 2=medium, and 3=strong). Additionally, lymphatic microvessel density in the D2-40 stained sections was counted. Vascular endothelial growth factor receptor-3 (quantification score 9.42 ± 2.94) was significantly more strongly expressed than vascular endothelial growth factor receptor-2 (quantification score 2.15 ± 2.42, p < 0.001). Furthermore, epidermal vascular endothelial growth factor expression was negatively correlated with the intratumoural lymphatic vessel density, and the ratio of small lymphatics to large lymphatics was much higher in intratumoural tissue than in paratumoural tissue and in intraindividual control tissue, suggesting a lymphangiogenetic potential of sebaceous carcinoma.

Analysis of hedgehog signaling in periocular sebaceous carcinoma

PURPOSE

Sebaceous carcinoma (SC) is a clinical masquerader of benign conditions resulting in significant eye morbidity, sometimes leading to extensive surgical treatment including exenteration, and even mortality. Little is known about the genetic or molecular basis of SC. This study identifies the involvement of Hedgehog (Hh) signaling in periocular SC.

METHODS

Fifteen patients with periocular SC patients were compared to 15 patients with eyelid nodular basal cell carcinoma (nBCC; a known Hh tumor), alongside four normal individuals as a control for physiological Hh expression. Expression of Patched 1 (PTCH1), Smoothened (SMO), and glioma-associated zinc transcription factors (Gli1 and Gli2) were assessed in histological sections using immunohistochemistry and immunofluorescence (IF) techniques. Antibody specificity was verified using Western-blot analysis of a Gli1 over-expressed cancer cell line, LNCaP-Gli1. Semi-quantification compared tumors and control tissue using IF analysis by ImageJ software.

RESULTS

Expression of the Hh pathway was observed in SC for all four major components of the pathway. PTCH1, SMO, and Gli2 were more significantly upregulated in SC (P < 0.01) compared to nBCC. Stromal expression of PTCH1 and Gli2 was observed in SC (P < 0.01). In contrast, stromal expression of these proteins in nBCC was similar or down-regulated compared to physiological Hh controls.

CONCLUSIONS

The Hh signaling pathway is significantly more upregulated in periocular SC compared to nBCC, a known aberrant Hh pathway tumor. Furthermore, the stroma of the SC demonstrated Hh upregulation, in particular Gli2, compared to nBCC. Targeting of this pathway may be a potential treatment strategy for SC.

Androgen receptor identification in the diagnosis of eyelid sebaceous carcinomas

PURPOSE

To assess the role of androgen receptor detection in diagnosing eyelid sebaceous carcinomas and to compare it with that of adipophilin.

DESIGN

Retrospective, clinicopathologic study.

METHODS

Ten sebaceous carcinomas (8 invasive, 2 intraepithelial only) were stained immunohistochemically for androgen receptors and were compared with adipophilin staining. Receptor staining also was performed on benign sebaceous tumors (a sebaceoma and an adenoma) and as controls on eyelid basal cell carcinomas, eyelid squamous cell carcinomas, conjunctival squamous dysplasias, and conjunctival melanomas.

RESULTS

All 8 patients with an invasive component of sebaceous carcinoma underwent a biopsy in which the tumor cells showed diffusely positive results for androgen receptors (>20% of cells and usually >40%) and positive results for adipophilin. Eight cases displaying an intraepithelial (or pagetoid) component of spread also showed diffusely positive results for androgen receptors and adipophilin in at least 1 of multiple biopsy samples from each patient. However, in 8 of 21 separate conjunctival biopsy specimens with intraepithelial cytologic atypia, adipophilin results were negative. A sebaceoma and a sebaceous adenoma also showed positive results for both of these biomarkers. Among the controls, squamous carcinomas and melanomas showed negative results for androgen receptors and adipophilin. Basal cell carcinomas displayed focal receptor positivity in fewer than 5% of cells and showed negative results for adipophilin.

CONCLUSIONS

Androgen receptors and adipophilin can separate sebaceous tumors immunohistochemically from squamous carcinomas and melanomas, which showed negative results for both, and from basal cell carcinomas, which showed positive receptor results in a distant minority of cells. Regarding intraepithelial (or pagetoid) spread, androgen receptor detection was more sensitive and reliable than adipophilin in highlighting this component of the disease.

Eyelid sebaceous carcinoma: clinicopathologic and multiparametric immunohistochemical analysis that includes adipophilin

PURPOSE

To evaluate the fine cytopathologic features and immunohistochemistry of eyelid sebaceous carcinoma.

DESIGN

Retrospective clinicopathologic study.

METHODS

Clinical records and microscopic glass slides of 12 patients diagnosed with sebaceous carcinoma were reviewed. Paraffin-embedded tissue recuts were immunoreacted for epithelial membrane antigen (EMA), Ber-EP4, p53, Ki-67, and adipophilin for cytoplasmic lipid. Invasive growth and intraepithelial spread were analyzed separately. Cytoplasmic and nuclear characteristics were correlated with the results of the immunohistochemical profiling.

RESULTS

Five patients experienced recurrences, but no metastases or tumor-related deaths were discovered. The nuclei in 11 invasive tumor cells were typically round with finely divided, granular, or smudgy chromatin without prominent margination at the nuclear membrane; they exhibited small punctate nucleoli. Positivity for EMA (both diffuse and focal), p53 (72% of nuclei), and Ki-67 (45% proliferation index) was demonstrated. Adipophilin positivity in vesicular and granular forms was detected in paraffin sections in all invasive tumors, most prominently in moderately differentiated and well-differentiated lesions. Among 9 cases exhibiting intraepithelial extensions, 6 showed mostly granular positivity and 3 vesicular positivity. p53 identified residual atypical intraepithelial cells when conjunctival epithelial sloughing occurred.

CONCLUSIONS

Immunohistochemistry can make significant contributions to the diagnosis of sebaceous carcinoma. p53 and vesicular granular adipophilin positivity were highly reliable in supplementing the routine microscopic diagnosis of infiltrative tumors and both can be used in paraffin sections, thereby obviating cumbersome oil red O staining of frozen sections. The cells found in intraepithelial spread were strongly EMA and p53 positive, with more granular than vesicular adipophilin positivity.

E-cadherin and β-catenin expression in sebaceous eyelid adenocarcinomas

BACKGROUND

Since the E-cadherin-catenin complex is of importance in the cancerogenesis of epithelial tumors, we examined the expression of E-cadherin and β-catenin in sebaceous adenocarcinomas of the eyelid and correlated the results with clinicopathological parameters.

METHODS

The study included histological specimen of 32 patients with sebaceous adenocarcinomas of the eyelid. The expression of E-cadherin, β-catenin, and Ki-67 nuclear antigen was analyzed by immunohistochemistry.

RESULTS

The membranous expression of E-cadherin and of β-catenin was reduced in 17 (53%) patients and 18 (56%) patients, respectively, while elevated cytoplasmic levels and a nuclear accumulation of β-catenin were found in 27 (84%) and six (19%) patients, respectively. The low expression of membranous β-catenin was associated with a high degree of tumor infiltration (p = 0.02), high amount of inflammation (p = 0.01), and high degree of poor tumor differentiation (p < 0.001). In a similar manner, a low membranous E-cadherin expression in tumors was significantly associated with poor tumor differentiation (p = 0.001) and high tumor cell proliferation rate (p = 0.004). The Ki-67 proliferation index was significantly higher in the group with low membranous E-cadherin expression than in the group with high membranous E-cadherin expression (62.3 ± 20.8 versus 42.1 ± 15.3; p = 0.004). The membranous E-cadherin expression and the membranous β-catenin expression were significantly associated with each other (Fisher's exact probability test, p = 0.03).

CONCLUSIONS

Sebaceous eyelid adenocarcinomas showed a decrease in the membranous expression of E-cadherin and of β-catenin. These changes were associated with poor tumor differentiation and an increase in the tumor infiltration and inflammation, pointing at a potential role of a low E-cadherin and low β-catenin expression for poor prognosis of sebaceous eyelid adenocarcinomas. Correspondingly, the cell proliferation index and the expression of E-cadherin were inversely correlated with each other. The findings suggest that the immunohistochemical detection of a low E-cadherin and low β-catenin expression may help in the examination and staging of sebaceous eyelid adenocarcinomas.

Activator protein-1 activity regulates epithelial tumor cell identity

To examine the consequences of inhibiting activator protein-1 (AP-1) transcription factors in skin, transgenic mice were generated, which use the tetracycline system to conditionally express A-FOS, a dominant negative that inhibits AP-1 DNA binding. Older mice develop mild alopecia and hyperplasia of sebaceous glands, particularly around the eyes. When A-FOS was expressed during chemical-induced skin carcinogenesis, mice do not develop characteristic benign and malignant squamous lesions but instead develop benign sebaceous adenomas containing a signature mutation in the H-ras proto-oncogene. Inhibiting AP-1 activity after tumor formation caused squamous tumors to transdifferentiate into sebaceous tumors. Furthermore, reactivating AP-1 in sebaceous tumors results in a reciprocal transdifferentiation into squamous tumors. In both cases of transdifferentiation, individual cells express molecular markers for both cell types, indicating individual tumor cells have the capacity to express multiple lineages. Molecular characterization of cultured keratinocytes and tumor material indicates that AP-1 regulates the balance between the wnt/beta-catenin and hedgehog signaling pathways that determine squamous and sebaceous lineages, respectively. Chromatin immunoprecipitation analysis indicates that c-Jun binds several wnt promoters, which are misregulated by A-FOS expression, suggesting that members of the wnt pathway can be a primary targets of AP-1 transcriptional regulation. Thus, AP-1 activity regulates tumor cell lineage and is essential to maintain the squamous tumor cell identity.

An illustrative case of Muir-Torre syndrome: contribution of immunohistochemical analysis in identifying indicator sebaceous lesions

BACKGROUND

Muir-Torre syndrome (MTS) is an autosomal dominant genodermatosis characterized by the association of at least 1 cutaneous sebaceous tumor and 1 internal malignancy, often arising in the gastrointestinal tract. It is secondary to germline mutations in DNA mismatch repair genes, mainly MLH-1 and MSH-2.

OBSERVATIONS

We report the case of a 54-year-old man with a 2-year history of skin-colored papules clinically reminiscent of large sebaceous hyperplasias on the nose and back, but histologically diagnosed as sebaceous adenomas and epitheliomas. His family history was positive for colon cancer in the mother and 2 brothers. A colonoscopy done during the hospitalization revealed 2 sessile polyps in the left colon, both showing a low-grade dysplasia on the biopsy specimen. Immunohistochemical staining performed on the cutaneous and colic biopsy specimens revealed a lack of expression of MSH-2 and MSH-6. Genetic testing revealed microsatellite instability in the colon and cutaneous tumors.

CONCLUSION

The immunohistochemical testing for MSH-2, MSH-6, and MLH-1 is useful for rapid identification of an underlying mismatch repair defect and early diagnosis of MTS.

Cytokeratin 15 expression in neoplasms with sebaceous differentiation

BACKGROUND

Recent studies have demonstrated that the cytokeratin 15 (CK15)-positive stem cells located in the hair follicle bulge are also involved in sebaceous gland renewal. No previous studies have dealt with the CK15 expression in sebaceous neoplasms.

METHODS

We studied the CK15 expression in 30 sebaceous neoplasms including 10 sebaceomas (sebaceoma defined as a distinct benign neoplasm with sebaceous differentiation), 10 sebaceous neoplasms of Muir-Torre syndrome, and 10 sebaceous carcinomas, in addition to that in the mantles of normal hair follicles.

RESULTS

CK15 was positive in the undifferentiated sebocytes of the mantles. All 10 sebaceomas showed CK15 expression in the basaloid, germinative cells. Both sebaceous neoplasms in Muir-Torre syndrome and sebaceous carcinomas demonstrated negative or only a focal positive reaction, including the occasional aberrant expression in matured sebocytes, to CK15.

CONCLUSIONS

CK15 may be a useful marker for stem cells with a sebaceous fate, and a constant CK15 expression in sebaceomas supported the hypothesis that sebaceoma is a benign neoplasm of sebaceous germinative cells in the mantles. The similar staining pattern of CK15 between sebaceous neoplasms in Muir-Torre syndrome and sebaceous carcinomas may be one piece of evidence supporting the hypothesis that most sebaceous neoplasms in Muir-Torre syndrome are low-grade sebaceous carcinomas.

Expression of retinoid receptors in sebaceous cell carcinoma

PURPOSE

The aim of this study is to investigate whether there are any abnormalities in the in vivo expression of retinoid acid receptors (RAR-alpha, RAR-beta and RAR-gamma) and retinoid X receptors (RXR-alpha, RXR-beta and RXR-gamma) in sebaceous cell carcinoma.

METHODS

Expression of retinoid receptors in paired specimens of cancerous tissues (n = 10) and adjacent normal tissues (n = 10) from 10 patients with sebaceous cell carcinoma was studied immunohistochemically by using anti-retinoid receptor antibodies.

RESULTS

In eight of the 10 normal tissue samples, all six receptors were expressed. In the other two samples, all receptors were expressed except RAR-gamma (one sample) or RXR-gamma (two samples). Five tumours (50%) lacked RAR-alpha; RAR-alpha expression was lower in tumours than in normal tissues in eight of 10 cases. RAR-beta was expressed in the cytoplasm of nine of 10 tumours; RAR-beta expression was at least as high in tumours as in normal tissue in eight of 10 cases. Two tumours lacked RAR-gamma; three tumours had lower RAR-gamma expression than paired normal epithelium; four had the same RAR-gamma expression, and one had higher RAR-gamma expression. RXR-alpha expression was strong in all normal tissues and tumour samples. Ten tumours lacked RXR-beta and all 10 tumours lacked RXR-gamma expression.

CONCLUSIONS

Diminished RXR-beta and RXR-gamma expression might be related to the development of sebaceous cell carcinoma. Additional studies are required to establish whether the defects in RAR expression in sebaceous cell carcinoma might affect the potential response of this tumour to treatment with retinoids.

Correlation of the expression of telomerase RNA with risk factors for recurrence of sebaceous gland carcinoma

AIMS

To investigate the expression of human telomerase gene RNA (hTR) and human telomerase reverse transcriptase (hTRT) in eyelid sebaceous gland carcinoma and to evaluate risk factors for sebaceous carcinoma recurrence.

METHODS

The expression patterns of hTR and hTRT were detected by in situ hybridization (ISH) in paraffin-embedded samples of 55 eyelid sebaceous gland carcinoma, 12 chalazia, and four sebaceous adenoma. The proliferation index (PI) of sebaceous gland carcinoma was determined by Ki-67 immunolabeling and the results were compared with the expression of hTR and hTRT. Several factors for recurrence of sebaceous gland carcinoma were evaluated by statistical analysis.

RESULTS

Expression of hTR and hTRT was present mainly in the sebaceous gland carcinoma tissues and not in adjacent tissues of carcinoma, chalazia, and sebaceous adenoma. The prevalence of hTR, hTRT, and Ki-67 expression in 55 sebaceous carcinoma samples were 84.45%, 58.1%, and 78.18%, respectively. hTR expression was highly associated with the degree of carcinoma differentiation (P<0.001) and hTRT expression was correlated with the proliferation index as determined by Ki-67 staining (P<0.005). There was a correlation between the recurrence of sebaceous gland carcinoma and the patient's onset age (OR=0.914, P<0.05), as well as the time to first treatment (OR=1.163, P<0.01).

CONCLUSIONS

Telomerase may play an important role in the carcinogenesis of sebaceous gland carcinoma, and expression of hTR and hTRT combined with other features of sebaceous gland carcinoma may be helpful for the diagnosis and evaluation of clinical prognosis. Risk factors for recurrence of sebaceous gland carcinoma are patients' onset age and the time to first treatment.

Carcinoid-like pattern in sebaceous neoplasms: another distinctive, previously unrecognized pattern in extraocular sebaceous carcinoma and sebaceoma

This report emphasizes a carcinoid-like pattern, a previously unrecognized feature in cutaneous sebaceous neoplasms. We report 7 patients with sebaceous tumors in which neoplastic cells were arranged in a trabecular and ribbon-like pattern or formed rosettes/pseudorosettes. The cases included 6 men and 1 woman, with their ages at the diagnosis ranging from 43 to 87 years (median age, 59). All patients presented with a solitary lesion. Locations were the scalp (n = 6) and forearm (n = 1). The carcinoid-like arrangement of neoplastic cells was the sole pattern in 4 cases, and in 3 cases the so-called labyrinthine/sinusoidal and/or rippled patterns were seen in addition. Sebaceous differentiation in the form of mature sebocytes varied from almost none to approximately 10%. Although the neoplasm appeared benign architecturally, the presence of cytologic atypia qualified 2 tumors as low-grade carcinomas. Four lesions represented sebaceomas, and in 1 case microscopic delineation between a carcinoma and sebaceoma was difficult. No neuroendocrine differentiation was demonstrated immunohistochemically, histochemically, and ultrastructurally. Electron microscopic examination performed in 1 case of carcinoma revealed lipid vacuoles in a minority of cells. There were no membrane-bound neuroendocrine granules. Rare cells contained peculiar large helioid inclusions. We conclude that the carcinoid-like pattern is another distinctive pattern indicative of sebaceous neoplasms. This pattern seems to be closely related to the rippled and labyrinthine/sinusoidal patterns, as exemplified by our cases, in which these arrangements sometimes occurred simultaneously.

Retinoid Receptor Subtypes in Sebaceous Cell Carcinoma of the Eyelid

PURPOSE

To study retinoid receptor expression in sebaceous cell carcinoma of the eyelid.

METHODS

Expression of retinoid receptors (RAR alpha, beta, and gamma and RXR alpha, beta, and gamma) in tumor specimens from 10 patients with sebaceous cell carcinoma of the eyelid and in 3 normal incidental tarsus specimens from healthy adults without cancer was studied immunohistochemically by using antiretinoid receptor antibodies.

RESULTS

In all 3 specimens of normal tarsus, all 6 retinoid receptors were expressed. RARalpha expression was absent in 3 tumors and was decreased in 3 tumors compared with expression in the control tissues. RARbeta expression in carcinomas was primarily perinuclear; 6 tumors showed increased RARbeta expression compared with controls. RARgamma expression was absent in 4 tumors and was decreased in 2 tumors compared with controls. RXRalpha nuclear expression was decreased compared with controls in 5 tumors. RXRbeta expression was low in 7 tumors. RXRgamma expression was absent in 6 tumors.

CONCLUSIONS

Aberrant expression of retinoid receptors in sebaceous cell carcinoma of the eyelid might play a role in the pathogenesis and progression of this carcinoma.

Ki-67 Labeling Index as a Marker of Malignancy in Ocular Surface Neoplasms

PURPOSE

To evaluate the relationships among histopathological type, clinical malignant grade, and Ki-67 labeling index (LI) in sebaceous gland carcinoma (SGC), conjunctival squamous cell carcinoma (SCC), and conjunctival intraepithelial neoplasia (CIN), with pterygium and normal conjunctiva as controls.

METHODS

This retrospective study was conducted at the Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan. We used tissue specimens obtained from 20 patients (four SGC, four SCC, four CIN, four pterygium, and four normal conjunctiva). Ki-67 immunohistochemical analysis was performed in all 20 cases.

RESULTS

The Ki-67 labeling index (LI) was 46.1 +/- 3.0% (average +/- SD) in SGC, 28.4 +/- 4.5% in SCC, 20.0 +/- 7.2% in CIN, 9.0 +/- 2.2% in pterygium, and 6.8 +/- 2.3% in normal conjunctiva. Ki-67 LI was significantly (Mann-Whitney U test, P < 0.05) higher in SGC than in SCC, and higher, but not significantly, in SCC than in CIN. Ki-67 LI was significantly (P < 0.05) higher in SCC and CIN than in pterygium.

CONCLUSIONS

These results suggest that Ki-67 LI may be a sensitive marker for ocular malignant tumor grading.

Basal cell carcinoma with sebaceous differentiation

Some authors have used sebaceous epithelioma as a synonym for basal cell carcinoma (BCC) with sebaceous differentiation. However, our review of the literature revealed that definite cases of BCC with sebaceous differentiation that provide adequate clinical and histopathologic information are scarce. We present the case of a 72-year-old woman with a pigmented nodular lesion on her right ala nasi region, clinically diagnosed as pigmented BCC. Histopathologically, this nodular lesion, which was completely excised, showed typical features of BCC. It was noteworthy that within one aggregation of the presented BCC, tiny and small duct-like structures lined by cornified layers with a crenulated inner surface were seen. Vacuolated cells were scattered within a few aggregations, and they had foamy, bubbly cytoplasm and starry nuclei. The vacuolated cells were immunohistochemically positive for epithelial membrane antigen (EMA). These histopathologic findings demonstrated unquestionable sebaceous differentiation in this BCC, namely BCC with sebaceous differentiation, which should be distinguishable from both sebaceoma and sebaceous carcinoma. The small duct-like structures lined by eosinophilic cuticle, indicating apocrine differentiation, were also observed in this BCC.

Loss of p21(WAF1) compartmentalisation in sebaceous carcinoma compared with sebaceous hyperplasia and sebaceous adenoma

AIMS

Regulation of cell cycle progression is a fundamental control process, linked to cellular differentiation and apoptosis in normal tissues. p21(WAF1) is a nuclear protein that regulates cell cycle progression. p21(WAF1) can be transcriptionally upregulated by p53, but may be activated independently of p53-for example, during terminal differentiation. Loss of topological control of p21(WAF1) expression is an early feature of malignancy in the colorectal system. Similar to the colonic mucosa, sebaceous glands contain cells that are constantly going through a process of cell division, differentiation, and cell death. This study investigated the expression of p53, p21(WAF1), and the proliferation marker Ki67 in normal sebaceous glands, sebaceous adenoma, sebaceoma, and sebaceous carcinoma.

METHODS

Serial sections were stained with monoclonal antibodies to p21(WAF1), p53, and Ki67 (MIB1) using standard immunohistochemical techniques.

RESULTS

In normal sebaceous glands, p21(WAF1) positive cells were only seen within the differentiating compartment, which was spatially distinct from the cycling peripheral Ki67 positive cells. In sebaceous adenoma and sebaceoma, topological control was maintained, with the distribution of markers being similar to that seen in normal sebaceous glands. Loss of topological control of markers of cellular control was seen in sebaceous carcinoma only. This contrasts with colonic tumours, in which loss of p21 compartmentalisation is seen in adenomas at an early stage of tumour progression.

CONCLUSION

This work confirms the hypothesis that the dysregulation of cell cycle progression is an important process in the development of malignancy within sebaceous glands, although loss of topological control was seen only in sebaceous carcinoma.

Sebaceous carcinoma of the lung: histologic and immunohistochemical characterization of an unusual pulmonary neoplasm: report of a case and review of the literature

Sebaceous neoplasms, including carcinomas, are tumors most often seen around the eye and eyelid. Cases of extraorbital sebaceous tumors associated with skin adnexa are less common. The parotid gland may also be a source for sebaceous neoplasms, and cases associated with minor salivary gland tissue have also been reported. Once beyond the oropharynx, individual cases of pharyngeal and laryngeal sebaceous tumors are reported. The case of a patient with primary sebaceous carcinoma of the bronchus is presented. Our case is that of an endobronchial mass that has histopathologic features of a sebaceous carcinoma, with predominance of areas with morphologically classic sebaceous differentiation, confirmed by oil red O stain for lipid, analyzed by immunohistochemistry and evaluated ultrastructurally. This unique tumor extends the spectrum of extraocular, extracutaneous neoplasms with sebaceous differentiation from existing single reports in the hypopharyx and larynx to now include bronchus.

MUC1 and sialoglycan expression associated with cytotoxic T lymphocyte infiltration in eyelid malignant tumors

PURPOSE

To elucidate the relation between infiltrating cytotoxic T lymphocytes and the expression of MUC1 and sialoglycans in malignant eyelid tumors.

METHODS

The distribution of MUC1, Maackia amurensis lectin-II (MAL-II)-recognized sialoglycan, and CD8-positive T lymphocytes was examined histochemically in 14 patients with malignant eyelid tumors: three squamous cell carcinomas, six sebaceous gland carcinomas, and five basal cell carcinomas. The density of CD8-positive cells was examined and correlated with MUC1 and sialoglycan expression.

RESULTS

MUC1 was identified in squamous cell carcinoma and sebaceous gland carcinoma, but not in basal cell carcinoma. CD8-positive cells were more densely distributed in those squamous cell and sebaceous gland carcinoma cases that were more intense in MUC1 expression and weaker in MAL-II binding. Tumors with a strong expression of both MUC1 and MAL-II-bound sialoglycans showed few CD8-positive cells.

CONCLUSIONS

MUC1 with few sialoglycans is likely to induce an intense infiltration of CD8-positive cytotoxic T lymphocytes in eyelid cancers.

[Immunohistochemical distribution of keratin in malignant tumors of eyelids]

The type and distribution of keratins (K) in malignant tumors of eyelids were examined immunohistochemically to understand the pathomechanism of intercellular interactions. All of the tumor cells in the basal cell carcinoma were positive for K14, which is specific for basal cells, whereas all of them were negative for K10, which is specific for suprabasal layers in stratified squamous epithelia. These findings suggest that basal cell carcinoma may consist of uniform, basal cell-like tumor cells. On the other hand, the squamous cell carcinoma and sebaceous carcinoma, which were positive for either K14 or K10 to varying extent, may consist of various tumor cells with different types and degrees of differentiation. In these tumors, K14 was frequently detected throughout the border cells of the tumor mass. Apoptotic bodies were detected at the region where this continuous distribution of K14 was interrupted. These findings may help to clarify the pathomechanism of the interactions between the tumor cells and stromal cells.

Ocular sebaceous carcinoma. Two unusual cases, and their histochemical and immunohistochemical findings

BACKGROUND

Since sebaceous carcinomas with a poor prognosis arising from the cutaneous adnexae of the eyelid are sometimes difficult to differentiate from squamous cell carcinoma or basal cell carcinoma on clinical and histopathological findings, definite differentiation between these tumors by additional methods is necessary.

OBJECTIVE AND METHODS

To clarify the usefulness of histochemical and immunohistochemical examinations in diagnosing ocular sebaceous carcinoma, histochemical and immunohistochemical studies were carried out on the 2 patients with unusual ocular sebaceous carcinoma.

RESULTS

The findings of ocular sebaceous carcinoma, at least in our 2 cases, were almost identical to those of extraocular sebaceous carcinoma.

CONCLUSION

Immunohistochemical detection of human milk fat globules subclass 1, human milk fat globules subclass 2, and breast carcinoma-associated antigen 225 was useful for diagnosing ocular sebaceous carcinomas as well as extraocular ones.